1. Field of the Invention
This invention relates to a new and improved apparatus for severing or cutting-off lengths of plastic or resin material from a continuous strip or sheet and, particularly, to a machine or process whereby a cutting-off operation may be effectively accomplished without damaging the material.
2. Description of the Prior Art
There have been two conventional methods of cutting plastic or resin sheet material into suitable lengths as it is extruded. A hydraulic shear has been used for relatively tough and heavy sheet material, such as a polycarbonate. This method, however, is not satisfactory for a sheet of resin in the nature of an acrylic or polystyrene since it tends to cause a shattering of its edges. The usual method of cutting the latter type of resin is to employ a traveling cut-off saw, but this has several disadvantages. In the first place, it generates a considerable amount of sawdust which contaminates air in the room and adheres to the sheet, causing a cleaning problem. In the second place, the sawing operation takes a measurable period of time to cut across the width of the material, and makes it difficult to maintain an absolutely square cut. Finally, the saw is extremely noisy and represents a problem of ear damage to employees working in the area for long periods of time.
There has been a need for an improved cutting-off method, machine or apparatus which will have the ability to substantially simultaneously cut-off the full width of a piece of material, that will be effective for various types of resin or thermoplastic materials, that will assure a full length accurate cut, and that will eliminate health hazards and loss of time that exist in connection with the use of a traveling saw.